As the number of computer systems have increased, so has the amount of information available to users of those computer systems. Many computer systems are connected together through networks, allowing users in many different locations to access information from a wide variety of information sources throughout the world.
When a user requests information from a remote computer system, the request often passes from the requesting system through one or more other computer systems prior to arriving at the remote system having requested the information. The requested information is then retrieved, packaged and sent from the remote system, passing through a similar number of computer systems on its way back to the requesting system.
Some information is more desirable, and is therefore accessed by greater numbers of users than seen with respect to less desirable information. Further, some users may access certain information frequently. Multiple instances of retrieving the same information utilizes connection bandwidth and web server resources that would otherwise be available to use for other tasks.
Some networked systems employ web cache devices that make a local copy of retrieved information, to avoid multiple remote retrievals of the same information. Web cache devices also minimize the latency associated with retrieval of information, since cached information is retrieved much more quickly than if the information were retrieved from its original remote location.
Web cache devices may also be associated with specific web servers and placed at various geographical locations, in order to reduce the load on the web server, and to ensure that information requested from the web server is delivered in a timely manner.
In systems employing web cache devices, if a web cache device fails, cached information associated with the failed web cache device typically becomes unavailable. As such, requests for information previously cached on the failed web cache device will typically result in the information being retrieved from its original remote location.